The present invention relates generally to dental hygiene devices. More particularly, this invention relates to a device carrying a dental hygiene element that is easy to assemble and that allows the user to easily identify the dental hygiene element mounted to the device. Additionally, this invention relates to a method for conveniently assembling dental hygiene elements to dental hygiene devices.
Various devices are known in the art for cleaning and stimulating the teeth and gums to maintain good dental hygiene. The most ubiquitous of such devices is the conventional toothbrush. Another popular cleaning and stimulating device is an interproximal toothbrush such as one of the many different interproximal toothbrushes available from John O. Butler Company of Chicago, Ill. Still other types of commonly used cleaning and stimulating devices are rubber stimulators and picks mounted in appropriate handles.
A dental hygiene device thus comprises a brush or other cleaning or stimulating element attached to the handle of the device. The present invention is applicable to dental hygiene devices such as those designed with a brush or other element mounted to a separate carrying member that is removably attached to a handle. One such device is described in U.S. Pat. application Ser. No. 08/057,195 which is entitled xe2x80x9cDental Hygiene System,xe2x80x9d filed Mar. 8, 1998 and assigned to the present assignee, John O. Butler Company, and which is incorporated herein by reference. The present invention is also applicable to conventional dental hygiene devices having an element that is mounted to a handle comprising a single, integral unit. Assembly of the brush or other cleaning or stimulating element to the dental hygiene device is accomplished by permanently securing a stem or other part of the element either to a portion of the handle of the device, as in the latter case, or to a separate carrying member that is removably attached to the handle, as discussed above.
Cleaning or stimulating elements come in a variety of sizes and shapes. However, in all cases, these elements are small because they are intended for use in the mouth. As a result, properly assembling the brush or other cleaning or stimulating element either directly to the dental hygiene device or to a separate, removable carrying member can be a delicate and challenging process.
Properly and reliably securing the stem of the brush or other cleaning or stimulating element to the handle of the dental hygiene device or to a removable carrying member is important because in use these elements are subject to substantial pull-out forces. The conventional method of permanently assembling the brush or other element to the handle of the dental hygiene device is to make the handle or removable carrying member out of plastic and to mold the plastic around the stem of the element as the handle or removable carrying member is formed. This allows the plastic to closely conform to the shape of the stem, generally retaining it securely.
Nonetheless, under certain circumstances the stem may work its way out of its support. For instance, the stem used with many dental hygiene elements consists of two elongated wires twisted around each other in a spiral configuration. This twisted wire stem may xe2x80x9cunscrewxe2x80x9d from the molded plastic around it under extreme circumstances. This tendency of the stem to work its way out of its support may be minimized by providing a bend in the stem before molding.
As those skilled in the art will recognize, accurately positioning the stem in the mold is very difficult. The process, whether done by hand or by robotics, is cumbersome and time-consuming because of the difficulty of picking up the stem of the small element and properly orienting it in the mold. The process is even more difficult if the stem is bent to aid retention, as discussed immediately above. Locating the stem in its proper place in the mold is essential, because the mold may be damaged if the element is misaligned and lays across the parting line when the mold closes. Also, if brushes or elements with stems of various diameters are to be used, these variations must be accommodated.
Accordingly, the development of a method for permanently assembling a dental hygiene element to the handle of a dental hygiene device or to a removable carrying member that is easier, faster and more economical than presently available methods would be highly desirable. This method of assembly should allow the stem of the brush or other cleaning or stimulating element to be secured to the handle or to the removable carrying member in a manner that increases its resistance to pull-out. Further, this technique should be able to accommodate brushes or elements with stems of varying diameters.
Moreover, once the handle of the dental hygiene device or the removable carrying member has been completely assembled, the consumer or user should be able to easily identify the brush or other element mounted to it, particularly where identification of the element itself is difficult because of its overall small size and because variations among different elements of the same type are subtle and difficult to perceive.
Accordingly, one object of this invention is to provide a method of assembling a brush or other cleaning or stimulating element to the handle of a dental hygiene device or to a removable carrying member that is easier, faster and more economical than conventional methods of manufacture.
A further object of this invention is to provide a method of securing the stem of a brush or other cleaning or stimulating element to the handle of the dental hygiene device or to a removable carrying member in a manner that firmly holds the stem in place and thereby increases the retention of the stem in the device.
Yet another object of this invention is to provide a method of assembling a brush or other cleaning or stimulating element to the handle of a dental hygiene device or to a removable carrying member that accommodates brushes or elements with stems of different diameters.
The present invention involves providing a dental hygiene device with first and second intersecting cavities in the area which is to receive the stem of a brush or other cleaning or stimulating element. Preferably, the first and second cavities are generally perpendicular. The stem of the brush or other element is inserted into the first cavity and a plug is inserted into the second cavity to engage with and lock the stem in place. Preferably, the stem is either pre-bent to accept the plug or bent by the plug itself to enhance retention of the brush or other element. Finally, plugs may be provided with heads of different colors or different shapes corresponding to a particular feature of the brush or other element that is otherwise difficult to visually perceive.